billboards are getting covered by terrian

CesiumJS
1

Hi,

I have overlaid a cesium terrain on top of the cesium globe. And I am positioning the billboards on top of the terrain by left click. But these billboards are getting covered by terrain. How to overcome these issues. I have used the height reference as clamp to ground, but it is throwing an error. Please help

Regards

Jalluri Chaitanya

sandcastle example: https://cesiumjs.org/Cesium/Apps/Sandcastle/index.html#c=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